WEDNESDAY, Feb. 8, 2017 (HealthDay News) -- If you're on the fence about joining a gym, consider this: Health club members exercise more and have better heart health, according to a new study.

Researchers from Iowa State University found men and women who have a gym membership get more aerobic and strength-training activity than those who don't.

"It's not surprising that people with a gym membership work out more, but the difference in our results is pretty dramatic," said study corresponding author Duck-chul Lee, an assistant professor of kinesiology.

"Gym members were 14 times more aerobically active than non-members and 10 times more likely to meet muscle-strengthening guidelines, regardless of their age and weight," Lee said in a university news release.

U.S. health officials recommend that adults get 150 minutes of moderate or 75 minutes of vigorous aerobic activity each week.

Adults should also incorporate two days of weight lifting or other muscle-strengthening activities into their weekly routine. Muscle mass burns more energy and lowers the risk of obesity, the study authors explained.

Only half of all Americans meet the guidelines for aerobic activity, and only about 20 percent get the preferred amount of strength training, the study authors noted.

For the study, the researchers looked at data on more than 400 people, half of whom had a gym membership.

They found that 75 percent of the gym members met both aerobic and strength-training guidelines. But the same was true for only 18 percent of non-members.

Most of the people with a gym membership exceeded exercise recommendations, spending at least 300 minutes running, biking or engaging in some other cardio workout each week, according to the study.

Overall, the researchers noted health club members got nearly six more hours of physical activity a week than non-members.

"Cardiovascular disease is the leading cause of death for individuals in the U.S. As our paper shows, a health club membership is associated with more favorable cardiovascular health," said study co-author Elizabeth Schroeder.

Only 18 percent of Americans have a gym membership, the researchers pointed out. They said their findings suggest that incentives to boost health club membership could be beneficial.

"By joining a quality fitness facility, a new exerciser will be around like-minded people and have access to professionals who can help them be successful," said study co-author Warren Franke, a professor of kinesiology.

"Access to quality exercise equipment, social support and even the financial commitment may help spur someone to continue exercising. Not all facilities are the same, so it's important to find the 'right' fit," said Franke.